Resolve symbolic links when processing the locations of alternate
object stores, since failing to do so can lead to confusing and buggy
behavior.
* gc/resolve-alternate-symlinks:
object-file: use real paths when adding alternates
When adding an alternate ODB, we check if the alternate has the same
path as the object dir, and if so, we do nothing. However, that
comparison does not resolve symlinks. This makes it possible to add the
object dir as an alternate, which may result in bad behavior. For
example, it can trick "git repack -a -l -d" (possibly run by "git gc")
into thinking that all packs come from an alternate and delete all
objects.
rm -rf test &&
git clone https://github.com/git/git test &&
(
cd test &&
ln -s objects .git/alt-objects &&
# -c repack.updateserverinfo=false silences a warning about not
# being able to update "info/refs", it isn't needed to show the
# bad behavior
GIT_ALTERNATE_OBJECT_DIRECTORIES=".git/alt-objects" git \
-c repack.updateserverinfo=false repack -a -l -d &&
# It's broken!
git status
# Because there are no more objects!
ls .git/objects/pack
)
Fix this by resolving symlinks and relative paths before comparing the
alternate and object dir. This lets us clean up a number of issues noted
in 37a95862c6 (alternates: re-allow relative paths from environment,
2016-11-07):
- Now that we compare the real paths, duplicate detection is no longer
foiled by relative paths.
- Using strbuf_realpath() allows us to "normalize" paths that
strbuf_normalize_path() can't, so we can stop silently ignoring errors
when "normalizing" paths from the environment.
- We now store an absolute path based on getcwd() (the "future
direction" named in 37a95862c6), so chdir()-ing in the process no
longer changes the directory pointed to by the alternate. This is a
change in behavior, but a desirable one.
Signed-off-by: Glen Choo <chooglen@google.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git repack" learns to send cruft objects out of the way into
packfiles outside the repository.
* tb/repack-expire-to:
builtin/repack.c: implement `--expire-to` for storing pruned objects
builtin/repack.c: write cruft packs to arbitrary locations
builtin/repack.c: pass "cruft_expiration" to `write_cruft_pack`
builtin/repack.c: pass "out" to `prepare_pack_objects`
The way "git repack" creared temporary files when it received a
signal was prone to deadlocking, which has been corrected.
* jk/repack-tempfile-cleanup:
t7700: annotate cruft-pack failure with ok=sigpipe
repack: drop remove_temporary_files()
repack: use tempfiles for signal cleanup
repack: expand error message for missing pack files
repack: populate extension bits incrementally
repack: convert "names" util bitfield to array
When creating a multi-pack bitmap, remove per-pack bitmap files
unconditionally as they will never be consulted.
* tb/remove-unused-pack-bitmap:
builtin/repack.c: remove redundant pack-based bitmaps
When pruning objects with `--cruft`, `git repack` offers some
flexibility when selecting the set of which objects are pruned via the
`--cruft-expiration` option.
This is useful for expiring objects which are older than the grace
period, making races where to-be-pruned objects become reachable and
then ancestors of freshly pushed objects, leaving the repository in a
corrupt state after pruning substantially less likely [1].
But in practice, such races are impossible to avoid entirely, no matter
how long the grace period is. To prevent this race, it is often
advisable to temporarily put a repository into a read-only state. But in
practice, this is not always practical, and so some middle ground would
be nice.
This patch introduces a new option, `--expire-to`, which teaches `git
repack` to write an additional cruft pack containing just the objects
which were pruned from the repository. The caller can specify a
directory outside of the current repository as the destination for this
second cruft pack.
This makes it possible to prune objects from a repository, while still
holding onto a supplemental copy of them outside of the original
repository. Having this copy on-disk makes it substantially easier to
recover objects when the aforementioned race is encountered.
`--expire-to` is implemented in a somewhat convoluted manner, which is
to take advantage of the fact that the first time `write_cruft_pack()`
is called, it adds the name of the cruft pack to the `names` string
list. That means the second time we call `write_cruft_pack()`, objects
in the previously-written cruft pack will be excluded.
As long as the caller ensures that no objects are expired during the
second pass, this is sufficient to generate a cruft pack containing all
objects which don't appear in any of the new packs written by `git
repack`, including the cruft pack. In other words, all of the objects
which are about to be pruned from the repository.
It is important to note that the destination in `--expire-to` does not
necessarily need to be a Git repository (though it can be) Notably, the
expired packs do not contain all ancestors of expired objects. So if the
source repository contains something like:
<unreachable>
/
C1 --- C2
\
refs/heads/master
where C2 is unreachable, but has a parent (C1) which is reachable, and
C2 would be pruned, then the expiry pack will contain only C2, not C1.
[1]: https://lore.kernel.org/git/20190319001829.GL29661@sigill.intra.peff.net/
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One of our tests intentionally causes the cruft-pack generation phase of
repack to fail, in order to stimulate an exit from repack at the desired
moment. It does so by feeding a bogus option argument to pack-objects.
This is a simple and reliable way to get pack-objects to fail, but it
has one downside: pack-objects will die before reading its stdin, which
means the caller repack may racily get SIGPIPE writing to it.
For the purposes of this test, that's OK. We are checking whether repack
cleans up already-created .tmp files, and it will do so whether it exits
or dies by signal (because the tempfile API hooks both).
But we have to tell test_must_fail that either outcome is OK, or it
complains about the signal. Arguably this is a workaround (compared to
fixing repack), as repack dying to SIGPIPE means that it loses the
opportunity to give a more detailed message. But we don't actually write
such a message anyway; we rely on pack-objects to have written something
useful to stderr, and it does. In either case (signal or exit), that is
the main thing the user will see.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After we've successfully finished the repack, we call
remove_temporary_files(), which looks for and removes any files matching
".tmp-$$-pack-*", where $$ is the pid of the current process. But this
is pointless. If we make it this far in the process, we've already
renamed these tempfiles into place, and there is nothing left to delete.
Nor is there a point in trying to call it to clean up when we _aren't_
successful. It's not safe for using in a signal handler, and the
previous commit already handed that job over to the tempfile API.
It might seem like it would be useful to clean up stray .tmp files left
by other invocations of git-repack. But it won't clean those files; it
only matches ones with its pid, and leaves the rest. Fortunately, those
are cleaned up naturally by successive calls to git-repack; we'll
consider .tmp-*.pack the same as normal packfiles, so "repack -ad", etc,
will roll up their contents and eventually delete them.
The one case that could matter is if pack-objects generates an extension
we don't know about, like ".tmp-pack-$$-$hash.some-new-ext". The current
code will quietly delete such a file, while after this patch we'd leave
it in place. In practice this doesn't happen, and would be indicative of
a bug. Leaving the file as cruft is arguably a better behavior, as it
means somebody is more likely to eventually notice and fix the bug. If
we really wanted to be paranoid, we could scan for and warn about such
files, but that seems like overkill.
There's nothing to test with regard to the removal of this function. It
was doing nothing, so the behavior should be the same. However, we can
verify (and protect) our assumption that "repack -ad" will eventually
remove stray files by adding a test for that.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When git-repack exits due to a signal, it tries to clean up by calling
its remove_temporary_files() function, which walks through the packs dir
looking for ".tmp-$$-pack-*" files to delete (where "$$" is the pid of
the current process).
The biggest problem here is that remove_temporary_files() is not safe to
call in a signal handler. It uses opendir(), which isn't on the POSIX
async-signal-safe list. The details will be platform-specific, but a
likely issue is that it needs to allocate memory; if we receive a signal
while inside malloc(), etc, we'll conflict on the allocator lock and
deadlock with ourselves.
We can fix this by just cleaning up the files directly, without walking
the directory. We already know the complete list of .tmp-* files that
were generated, because we recorded them via populate_pack_exts(). When
we find files there, we can use register_tempfile() to record the
filenames. If we receive a signal, then the tempfile API will clean them
up for us, and it's async-safe and pretty battle-tested.
Note that this is slightly racier than the existing scheme. We don't
record the filenames until pack-objects tells us the hash over stdout.
So during the period between it generating the file and reporting the
hash, we'd fail to clean up. However, that period is very small. During
most of the pack generation process pack-objects is using its own
internal tempfiles. It's only at the very end that it moves them into
the names git-repack expects, and then it immediately reports the name
to us. Given that cleanup like this is best effort (after all, we may
get SIGKILL), this level of race is acceptable.
When we register the tempfiles, we'll record them locally and use the
result to call rename_tempfile(), rather than renaming by hand. This
isn't strictly necessary, as once we've renamed the files they're gone,
and the tempfile API's cleanup unlink() would simply become a pointless
noop. But managing the lifetimes of the tempfile objects is the cleanest
thing to do, and the tempfile pointers naturally fill the same role as
the old booleans.
This patch also fixes another small problem. We only hook signals, and
don't set up an atexit handler. So if we see an error that causes us to
die(), we'll leave the .tmp-* files in place. But since the tempfile API
handles this for us, this is now fixed for free. The new test covers
this by stimulating a failure of pack-objects when generating a cruft
pack. Before this patch, the .tmp-* file for the main pack would have
been left, but now we correctly clean it up.
Two small subtleties on the implementation:
- in the renaming loop, we can stop re-constructing fname_old; we only
use it when we have a tempfile to rename, so we can just ask the
tempfile for its path (which, barring bugs, should be identical)
- when renaming fails, our error message mentions fname_old. But since
a failed rename_tempfile() invalidates the tempfile struct, we'll
lose access to that string. Instead, let's mention the destination
filename, which is what most other callers do.
Reported-by: Jan Pokorný <poki@fnusa.cz>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`git repack` supports a `--pack-kept-objects` flag which more or less
translates to whether or not we pass `--honor-pack-keep` down to `git
pack-objects` when assembling a new pack.
This behavior has existed since ee34a2bead (repack: add
`repack.packKeptObjects` config var, 2014-03-03). In that commit, the
documentation was extended to say:
[...] Note that we still do not delete `.keep` packs after
`pack-objects` finishes.
Unfortunately, this is not the case when `--pack-kept-objects` is
combined with a `--geometric` repack. When doing a geometric repack, we
include `.keep` packs when enumerating available packs only when
`pack_kept_objects` is set.
So this all works fine when `--no-pack-kept-objects` (or similar) is
given. Kept packs are excluded from the geometric roll-up, so when we go
to delete redundant packs (with `-d`), no `.keep` packs appear "below
the split" in our geometric progression.
But when `--pack-kept-objects` is given, things can go awry. Namely,
when a kept pack is included in the list of packs tracked by the
`pack_geometry` struct *and* part of the pack roll-up, we will delete
the `.keep` pack when we shouldn't.
Note that this *doesn't* result in object corruption, since the `.keep`
pack's objects are still present in the new pack. But the `.keep` pack
itself is removed, which violates our promise from back in ee34a2bead.
But there's more. Because `repack` computes the geometric roll-up
independently from selecting which packs belong in a MIDX (with
`--write-midx`), this can lead to odd behavior. Consider when a `.keep`
pack appears below the geometric split (ie., its objects will be part of
the new pack we generate).
We'll write a MIDX containing the new pack along with the existing
`.keep` pack. But because the `.keep` pack appears below the geometric
split line, we'll (incorrectly) try to remove it. While this doesn't
corrupt the repository, it does cause us to remove the MIDX we just
wrote, since removing that pack would invalidate the new MIDX.
Funny enough, this behavior became far less noticeable after e4d0c11c04
(repack: respect kept objects with '--write-midx -b', 2021-12-20), which
made `pack_kept_objects` be enabled by default only when we were writing
a non-MIDX bitmap.
But e4d0c11c04 didn't resolve this bug, it just made it harder to notice
unless callers explicitly passed `--pack-kept-objects`.
The solution is to avoid trying to remove `.keep` packs during
`--geometric` repacks, even when they appear below the geometric split
line, which is the approach this patch implements.
Co-authored-by: Victoria Dye <vdye@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we write a MIDX bitmap after repacking, it is possible that the
repository would be left in a state with both pack- and multi-pack
reachability bitmaps.
This can occur, for instance, if a pack that was kept (either by having
a .keep file, or during a geometric repack in which it is not rolled up)
has a bitmap file, and the repack wrote a multi-pack index and bitmap.
When loading a reachability bitmap for the repository, the multi-pack
one is always preferred, so the pack-based one is redundant. Let's
remove it unconditionally, even if '-d' isn't passed, since there is no
practical reason to keep both around. The patch below does just that.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The '--write-midx -b packs non-kept objects' test in t7700-repack.sh
uses test_subcommand_inexact to check that 'git repack' properly adds
the '--honor-pack-keep' flag to the 'git pack-objects' subcommand.
However, the test_subcommand_inexact helper is more flexible than
initially designed, and this instance is the only one that makes use of
it: there are additional arguments between 'git pack-objects' and the
'--honor-pack-keep' flag. In order to make test_subcommand_inexact more
strict, we need to fix this instance.
This test checks that 'git repack --write-midx -a -b -d' will create a
new pack-file that does not contain the objects within the kept pack.
This behavior is possible because of the multi-pack-index bitmap that
will bitmap objects against multiple packs. Without --write-midx, the
objects in the kept pack would be duplicated so the resulting pack is
closed under reachability and bitmaps can be created against it. This is
discussed in more detail in e4d0c11c0 (repack: respect kept objects with
'--write-midx -b', 2021-12-20) which also introduced this instance of
test_subcommand_inexact.
To better verify the intended post-conditions while also removing this
instance of test_subcommand_inexact, rewrite the test to check the list
of packed objects in the kept pack and the list of the objects in the
newly-repacked pack-file _other_ than the kept pack. These lists should
be disjoint.
Be sure to include a non-kept pack-file and loose objects to be extra
careful that this is properly behaving with kept packs and not just
avoiding repacking all pack-files.
Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git repack" learned a new configuration to disable triggering of
age-old "update-server-info" command, which is rarely useful these
days.
* ps/repack-with-server-info:
repack: add config to skip updating server info
repack: refactor to avoid double-negation of update-server-info
By default, git-repack(1) will update server info that is required by
the dumb HTTP transport. This can be skipped by passing the `-n` flag,
but what we're noticably missing is a config option to permanently
disable updating this information.
Add a new option "repack.updateServerInfo" which can be used to disable
the logic. Most hosting providers have turned off the dumb HTTP protocol
anyway, and on the client-side it woudln't typically be useful either.
Giving a persistent way to disable this feature thus makes quite some
sense to avoid wasting compute cycles and storage.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By default, git-repack(1) runs `update_server_info()` to generate info
required for the dumb HTTP protocol. This can be disabled via the `-n`
flag, which then sets the `no_update_server_info` flag. Further down the
code this leads to some double-negation logic, which is about to become
more confusing as we're about to add a new config which allows the user
to permanently disable generation of the info.
Refactor the code to avoid the double-negation and add some tests which
verify that the flag continues to work as expected.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A bug that made multi-pack bitmap and the object order out-of-sync,
making the .midx data corrupt, has been fixed.
* tb/midx-bitmap-corruption-fix:
pack-bitmap.c: gracefully fallback after opening pack/MIDX
midx: read `RIDX` chunk when present
t/lib-bitmap.sh: parameterize tests over reverse index source
t5326: move tests to t/lib-bitmap.sh
t5326: extract `test_rev_exists`
t5326: drop unnecessary setup
pack-revindex.c: instrument loading on-disk reverse index
midx.c: make changing the preferred pack safe
t5326: demonstrate bitmap corruption after permutation
When a MIDX contains the new `RIDX` chunk, ensure that the reverse index
is read from it instead of the on-disk .rev file. Since we need to
encode the object order in the MIDX itself for correctness reasons,
there is no point in storing the same data again outside of the MIDX.
So, this patch stops writing separate .rev files, and reads it out of
the MIDX itself. This is possible to do with relatively little new code,
since the format of the RIDX chunk is identical to the data in the .rev
file. In other words, we can implement this by pointing the
`revindex_data` field at the reverse index chunk of the MIDX instead of
the .rev file without any other changes.
Note that we have two knobs that are adjusted for the new tests:
GIT_TEST_MIDX_WRITE_REV and GIT_TEST_MIDX_READ_RIDX. The former controls
whether the MIDX .rev is written at all, and the latter controls whether
we read the MIDX's RIDX chunk.
Both are necessary to ensure that the test added at the beginning of
this series continues to work. This is because we always need to write
the RIDX chunk in the MIDX in order to change its checksum, but we want
to make sure reading the existing .rev file still works (since the RIDX
chunk takes precedence by default).
Arguably this isn't a very interesting mode to test, because the
precedence rules mean that we'll always read the RIDX chunk over the
.rev file. But it makes it impossible for a user to induce corruption in
their repository by adjusting the test knobs (since if we had an
either/or knob they could stop writing the RIDX chunk, allowing them to
tweak the MIDX's object order without changing its checksum).
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While testing some ideas in 'git repack', I ran it with '--quiet' and
discovered that some progress output was still shown. Specifically, the
output for writing the multi-pack-index showed the progress.
The 'show_progress' variable in cmd_repack() is initialized with
isatty(2) and is not modified at all by the '--quiet' flag. The
'--quiet' flag modifies the po_args.quiet option which is translated
into a '--quiet' flag for the 'git pack-objects' child process. However,
'show_progress' is used to directly send progress information to the
multi-pack-index writing logic which does not use a child process.
The fix here is to modify 'show_progress' to be false if po_opts.quiet
is true, and isatty(2) otherwise. This new expectation simplifies a
later condition that checks both.
Update the documentation to make it clear that '-q' will disable all
progress in addition to ensuring the 'git pack-objects' child process
will receive the flag.
Use 'test_terminal' to check that this works to get around the isatty(2)
check.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Historically, we needed a single packfile in order to have reachability
bitmaps. This introduced logic that when 'git repack' had a '-b' option
that we should stop sending the '--honor-pack-keep' option to the 'git
pack-objects' child process, ensuring that we create a packfile
containing all reachable objects.
In the world of multi-pack-index bitmaps, we no longer need to repack
all objects into a single pack to have valid bitmaps. Thus, we should
continue sending the '--honor-pack-keep' flag to 'git pack-objects'.
The fix is very simple: only disable the flag when writing bitmaps but
also _not_ writing the multi-pack-index.
This opens the door to new repacking strategies that might want to keep
some historical set of objects in a stable pack-file while only
repacking more recent objects.
To test, create a new 'test_subcommand_inexact' helper that is more
flexible than 'test_subcommand'. This allows us to look for the
--honor-pack-keep flag without over-indexing on the exact set of
arguments.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Failures within `for` and `while` loops can go unnoticed if not detected
and signaled manually since the loop itself does not abort when a
contained command fails, nor will a failure necessarily be detected when
the loop finishes since the loop returns the exit code of the last
command it ran on the final iteration, which may not be the command
which failed. Therefore, detect and signal failures manually within
loops using the idiom `|| return 1` (or `|| exit 1` within subshells).
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To prevent the race described in an earlier patch, generate and pass a
reference snapshot to the multi-pack bitmap code, if we are writing one
from `git repack`.
This patch is mostly limited to creating a temporary file, and then
calling for_each_ref(). Except we try to minimize duplicates, since
doing so can drastically reduce the size in network-of-forks style
repositories. In the kernel's fork network (the repository containing
all objects from the kernel and all its forks), deduplicating the
references drops the snapshot size from 934 MB to just 12 MB.
But since we're handling duplicates in this way, we have to make sure
that we preferred references (those listed in pack.preferBitmapTips)
before non-preferred ones (to avoid recording an object which is pointed
at by a preferred tip as non-preferred).
We accomplish this by doing separate passes over the references: first
visiting each prefix in pack.preferBitmapTips, and then over the rest of
the references.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach `git repack` a new `--write-midx` option for callers that wish to
persist a multi-pack index in their repository while repacking.
There are two existing alternatives to this new flag, but they don't
cover our particular use-case. These alternatives are:
- Call 'git multi-pack-index write' after running 'git repack', or
- Set 'GIT_TEST_MULTI_PACK_INDEX=1' in your environment when running
'git repack'.
The former works, but introduces a gap in bitmap coverage between
repacking and writing a new MIDX (since the repack may have deleted a
pack included in the existing MIDX, invalidating it altogether).
Setting the 'GIT_TEST_' environment variable is obviously unsupported.
In fact, even if it were supported officially, it still wouldn't work,
because it generates the MIDX *after* redundant packs have been dropped,
leading to the same issue as above.
Introduce a new option which eliminates this race by teaching `git
repack` to generate the MIDX at the critical point: after the new packs
have been written and moved into place, but before the redundant packs
have been removed.
This option is compatible with `git repack`'s '--bitmap' option (it
changes the interpretation to be: "write a bitmap corresponding to the
MIDX after one has been generated").
There is a little bit of additional noise in the patch below to avoid
repeating ourselves when selecting which packs to delete. Instead of a
single loop as before (where we iterate over 'existing_packs', decide if
a pack is worth deleting, and if so, delete it), we have two loops (the
first where we decide which ones are worth deleting, and the second
where we actually do the deleting). This makes it so we have a single
check we can make consistently when (1) telling the MIDX which packs we
want to exclude, and (2) actually unlinking the redundant packs.
There is also a tiny change to short-circuit the body of
write_midx_included_packs() when no packs remain in the case of an empty
repository. The MIDX code does not handle this, so avoid trying to
generate a MIDX covering zero packs in the first place.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A number of these tests are focused only on pack-based bitmaps and need
to be updated to disable 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP' where
necessary.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a pipe, only the return code of the last command is used. Thus, all
other commands will have their return codes masked. Rewrite pipes so
that there are no git commands upstream so that we will know if a
command fails.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the test more hash-agnostic by renaming variables from "sha1" to
some variation of "oid" or "packid". Also, replace the regex,
`[0-9a-f]\{40\}` with `$OID_REGEX`.
A better name for "incrpackid" (incremental pack-id) might have been
just "packid". However, later in the test suite, we have other uses of
"packid". Although the scopes of these variables don't conflict, a
future developer may think that commit_and_pack() and
test_has_duplicate_object() are semantically related somehow since they
share the same variable name. Give them distinct names so that it's
clear these uses are unrelated.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The egrep expressions in this test suite were of the form `^$variable`.
Although egrep works just fine, it's overkill since we're not using any
extended regex. Replace egrep invocations with grep so that we aren't
swatting flies with a sledgehammer.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code to test that objects were not duplicated from the packfile was
duplicated many times. Extract the duplicated code into
test_has_duplicate_object() and use that instead.
Refactor the resulting extraction so that if the git command fails,
the return code is not silently lost.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code to test that objects were not missing from the packfile was
duplicated many times. Extract the duplicated code into
test_no_missing_in_packs() and use that instead.
Refactor the resulting extraction so that if any git commands fail,
their return codes are not silently lost.
Instead of verifying each file of `alt_objects/pack/*.idx` individually
in a for-loop, batch them together into one verification step.
The original testing construct was O(n^2): it used a grep in a loop to
test whether any objects were missing in the packfile. Rewrite this to
extract the hash using sed or cut, sort the files, then use `comm -23`
so that finding missing lines from the original file is done more
efficiently.
While we're at it, add a space to `commit_and_pack ()` for style.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since we have debugging-friendly alternatives to `test -f`, replace
instances of `test -f` with `test_path_is_file` so that if a command
ever fails, we get better debugging information.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code style for tests is to have statements on their own line if
possible. Move keywords onto their own line so that they conform with
the test style.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For shell scripts, the usual convention is for there to be no space
after redirection operators, (e.g. `>file`, not `> file`). Remove these
spaces wherever they appear.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since output is silenced when running without `-v` and debugging output
is useful with `-v`, remove redirections to /dev/null as it is not
useful.
In one case where the output of stdout is consumed, redirect the output
of test_commit to stderr.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 7328482253 (repack: disable bitmaps-by-default if .keep files
exist, 2019-06-29) taught repack to prefer disabling bitmaps to
duplicating objects (unless bitmaps were asked for explicitly).
But there's an easier way to do this: if we keep passing the
--honor-pack-keep flag to pack-objects when auto-enabling bitmaps, then
pack-objects already makes the same decision (it will disable bitmaps
rather than duplicate). Better still, pack-objects can actually decide
to do so based not just on the presence of a .keep file, but on whether
that .keep file actually impacts the new pack we're making (so if we're
racing with a push or fetch, for example, their temporary .keep file
will not block us from generating bitmaps if they haven't yet updated
their refs).
And because repack uses the --write-bitmap-index-quiet flag, we don't
have to worry about pack-objects generating confusing warnings when it
does see a .keep file. We can confirm this by tweaking the .keep test to
check repack's stderr.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Depending on various config options, a full repack may not be able to
build a reachability bitmap index (e.g., if pack.packSizeLimit forces us
to write multiple packs). In these cases pack-objects may write a
warning to stderr.
Since 36eba0323d (repack: enable bitmaps by default on bare repos,
2019-03-14), we may generate these warnings even when the user did not
explicitly ask for bitmaps. This has two downsides:
- it can be confusing, if they don't know what bitmaps are
- a daemonized auto-gc will write this to its log file, and the
presence of the warning may suppress further auto-gc (until
gc.logExpiry has elapsed)
Let's have repack communicate to pack-objects that the choice to turn on
bitmaps was not made explicitly by the user, which in turn allows
pack-objects to suppress these warnings.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After our test snippet finishes, the .keep file is left in place, making
it hard to do further tests of the auto-bitmap-writing code (since it
suppresses the feature completely). Let's clean it up.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Bitmaps aren't useful with multiple packs, and users with
.keep files ended up with redundant packs when bitmaps
got enabled by default in bare repos.
So detect when .keep files exist and stop enabling bitmaps
by default in that case.
Wasteful (but otherwise harmless) race conditions with .keep files
documented by Jeff King still apply and there's a chance we'd
still end up with redundant data on the FS:
https://public-inbox.org/git/20190623224244.GB1100@sigill.intra.peff.net/
v2: avoid subshell in test case, be multi-index aware
Fixes: 36eba0323d ("repack: enable bitmaps by default on bare repos")
Signed-off-by: Eric Wong <e@80x24.org>
Helped-by: Jeff King <peff@peff.net>
Reported-by: Janos Farkas <chexum@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A typical use case for bare repos is for serving clones and
fetches to clients. Enable bitmaps by default on bare repos to
make it easier for admins to host git repos in a performant way.
Signed-off-by: Eric Wong <e@80x24.org>
Helped-by: Jeff King <peff@peff.net>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We allow to keep existing packs by having companion .keep files. This
is helpful when a pack is permanently kept. In the next patch, git-gc
just wants to keep a pack temporarily, for one pack-objects
run. git-gc can use --keep-pack for this use case.
A note about why the pack_keep field cannot be reused and
pack_keep_in_core has to be added. This is about the case when
--keep-pack is specified together with either --keep-unreachable or
--unpack-unreachable, but --honor-pack-keep is NOT specified.
In this case, we want to exclude objects from the packs specified on
command line, not from ones with .keep files. If only one bit flag is
used, we have to clear pack_keep on pack files with the .keep file.
But we can't make any assumption about unreachable objects in .keep
packs. If "pack_keep" field is false for .keep packs, we could
potentially pull lots of unreachable objects into the new pack, or
unpack them loose. The safer approach is ignore all packs with either
.keep file or --keep-pack.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The closing quote of a test body by convention is always at the start
of line.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Git CodingGuidelines prefer the $(...) construct for command
substitution instead of using the backquotes `...`.
The backquoted form is the traditional method for command
substitution, and is supported by POSIX. However, all but the
simplest uses become complicated quickly. In particular, embedded
command substitutions and/or the use of double quotes require
careful escaping with the backslash character.
The patch was generated by:
for _f in $(find . -name "*.sh")
do
perl -i -pe 'BEGIN{undef $/;} s/`(.+?)`/\$(\1)/smg' "${_f}"
done
and then carefully proof-read.
Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Recent updates to "git repack" started to duplicate objects that
are in packfiles marked with .keep flag into the new packfile by
mistake.
* jk/repack-pack-keep-objects:
repack: s/write_bitmap/&s/ in code
repack: respect pack.writebitmaps
repack: do not accidentally pack kept objects by default
We want to make sure that the default behavior of git-repack,
without any options, continues to treat .keep files as it
always has. Adding an explicit --no-pack-kept-objects, as
ee34a2b did, is a much less interesting test, and prevented
us from noticing the bug fixed by 64d3dc9 (repack: do not
accidentally pack kept objects by default, 2014-06-10).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We currently have pack.writeBitmaps, which originally
operated at the pack-objects level. This should really have
been a repack.* option from day one. Let's give it the more
sensible name, but keep the old version as a deprecated
synonym.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The config option to turn on bitmaps is read all the way
down in the plumbing of pack-objects. This makes it hard for
other options in the porcelain of repack to make decisions
based on the bitmap setting. For example,
repack.packKeptObjects tries to kick in by default only when
bitmaps are turned on. But it can't do so reliably because
it doesn't yet know whether we are using bitmaps.
This patch teaches repack to respect pack.writebitmaps. It
means we pass a redundant command-line flag to pack-objects,
but that's OK; it shouldn't affect the outcome.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit ee34a2b (repack: add `repack.packKeptObjects` config
var, 2014-03-03) added a flag which could duplicate kept
objects, but did not mean to turn it on by default. Instead,
the option is tied by default to the decision to write
bitmaps, like:
if (pack_kept_objects < 0)
pack_kept_objects = write_bitmap;
after which we expect pack_kept_objects to be a boolean 0 or
1. However, that assignment neglects that write_bitmap is
_also_ a tri-state with "-1" as the default, and with
neither option given, we accidentally turn the option on.
This patch is the minimal fix to restore the desired
behavior for the default state. Further patches will fix the
more complicated cases.
Note the update to t7700. It failed to turn on bitmaps,
meaning we were actually confirming the wrong behavior!
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git-repack command always passes `--honor-pack-keep`
to pack-objects. This has traditionally been a good thing,
as we do not want to duplicate those objects in a new pack,
and we are not going to delete the old pack.
However, when bitmaps are in use, it is important for a full
repack to include all reachable objects, even if they may be
duplicated in a .keep pack. Otherwise, we cannot generate
the bitmaps, as the on-disk format requires the set of
objects in the pack to be fully closed.
Even if the repository does not generally have .keep files,
a simultaneous push could cause a race condition in which a
.keep file exists at the moment of a repack. The repack may
try to include those objects in one of two situations:
1. The pushed .keep pack contains objects that were
already in the repository (e.g., blobs due to a revert of
an old commit).
2. Receive-pack updates the refs, making the objects
reachable, but before it removes the .keep file, the
repack runs.
In either case, we may prefer to duplicate some objects in
the new, full pack, and let the next repack (after the .keep
file is cleaned up) take care of removing them.
This patch introduces both a command-line and config option
to disable the `--honor-pack-keep` option. By default, it
is triggered when pack.writeBitmaps (or `--write-bitmap-index`
is turned on), but specifying it explicitly can override the
behavior (e.g., in cases where you prefer .keep files to
bitmaps, but only when they are present).
Note that this option just disables the pack-objects
behavior. We still leave packs with a .keep in place, as we
do not necessarily know that we have duplicated all of their
objects.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some versions of touch (such as /usr/ucb/touch on Solaris)
do not know about the "-r" option. This would make sense as
a feature of test-chmtime, but fortunately this fix is even
easier.
The test does not care about the timestamp of the .keep file it
creates at all, only that it exists. For such a use case, with or
without portability issues around "-r", "touch" should not be used
in the first place.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
